Wafer processing tools and methods thereof

ABSTRACT

A wafer processing device may include a wafer exchanger including two or more blades, each of the two or more blades may be configured to receive a wafer, the two or more blades may be rotatable about an axis on a single horizontal plane, and the two or more blades may be movable between at least a load cup and a robot access location; wherein the load cup may include a wafer station that is vertically moveable relative a blade located in the load cup and may be configured to remove a wafer from a blade located in the load cup and place a wafer on a blade located in the load cup. Other devices, load cups and methods are also disclosed herein.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.16/738,798, filed on Jan. 9, 2020, which claims priority to U.S.Application Ser. No. 62/794,556, filed on Jan. 18, 2019, the disclosuresof which are incorporated by reference.

FIELD

The present application relates to wafer processing, and morespecifically to wafer processing tools and methods thereof.

BACKGROUND

Wafer processing tools, such as chemical mechanical polishing (CMP)systems, may encounter delays caused by the transfer of wafers betweendifferent processing stations. For example, processing may be delayed asrobots wait to access wafers before and/or after different processes.

SUMMARY

In a first aspect, a wafer processing device is provided. The waferprocessing device may include a wafer exchanger including two or moreblades, each of the two or more blades configured to receive a wafer,the two or more blades rotatable about an axis on a single horizontalplane, and the two or more blades movable between at least a load cupand a robot access location; wherein the load cup includes a waferstation that is vertically moveable relative a blade located in the loadcup and is configured to remove a wafer from a blade located in the loadcup and place a wafer on a blade located in the load cup.

In a second aspect, a load cup is provided. The load cup may include awafer station configured to receive a wafer, the wafer station moveablein a vertical direction between a first location where the wafer stationis spaced from a wafer and a second location where a wafer is receivedby the wafer station; and a notch in the wafer station, the notch sizedto receive a portion of a blade configured to support a wafer as thewafer station moves between the first location and the second location.

In a third aspect, a method of moving substrates is provided. The methodmay include providing a wafer exchanger including two or more blades,each of the two or more blades configured to receive a wafer, the two ormore blades rotatable about an axis on a single horizontal plane, andthe two or more blades movable between at least a load cup and a robotaccess location; placing a first wafer onto a blade of the waferexchanger located at the robot access location; placing a second waferfrom a head onto a blade of the wafer exchanger located at the load cup;rotating the wafer exchanger to a position where the second wafer islocated at the robot access location; removing the second wafer from thewafer exchanger; rotating the wafer exchanger to a position where thefirst wafer is located in the load cup; placing the first wafer into thehead; and placing a third wafer from the robot access location onto ablade of the wafer exchanger.

Numerous other aspects are provided in accordance with these and otherembodiments of the disclosure. Other features and aspects of embodimentsof the disclosure will become more fully apparent from the followingdetailed description, the appended claims, and the accompanyingdrawings.

BRIEF DESCRIPTION OF DRAWINGS

The drawings, described below, are for illustrative purposes only andare not necessarily drawn to scale. The drawings are not intended tolimit the scope of the disclosure in any way. Wherever possible, thesame or like reference numbers will be used throughout the drawings torefer to the same or like parts.

FIG. 1 illustrates a top, plan view of a chemical mechanical polishing(CMP) system according to embodiments disclosed herein.

FIG. 2 illustrates an enlarged, top, plan view of a wafer exchanger usedin a CMP system according to embodiments disclosed herein.

FIG. 3 illustrates a top, plan view of a load cup and a blade of a waferexchanger located within the load cup according to embodiments disclosedherein.

FIG. 4A illustrates a load cup in a retracted position according toembodiments disclosed herein.

FIG. 4B illustrates a load cup in an extended position according toembodiments disclosed herein.

FIGS. 5A-5D illustrate the operation of wafer exchangers in conjunctionwith other components of a CMP system according to embodiments describedherein.

FIG. 6 illustrates a top, plan view of a CMP system that includes one ormore rinse stations according to embodiments disclosed herein.

FIG. 7 illustrates a top plan view of a nebulizer that may be located ina rinse station in the CMP system of FIG. 6 according to embodimentsdisclosed herein.

DETAILED DESCRIPTION

Wafer processing devices, such as chemical mechanical polishing (CMP)systems, may encounter delays caused by the transfer of wafers betweendifferent processing stations. For example, processing may have to waitfor robots to gain access to wafers before and/or after differentprocesses, which may be time consuming. The wafer processing devicesdisclosed herein and illustrated in FIGS. 1-7 reduce wafer processingtimes relative to traditional wafer processing devices.

Reference is made to FIG. 1 , which illustrates a top plan view of achemical mechanical polishing (CMP) system 100. Although a CMP system isillustrated in FIG. 1 and described herein, the concepts disclosedherein may be applied to other wafer processing devices. The CMP system100 may include a polishing section 102 and a cleaning and dryingsection 104 that process (e.g., wash and/or polish) wafers 108 (a fewlabelled). The CMP system 100 may include other sections that performother processes on wafers. Wafers, as used herein, may include articlesused to make electronic devices or circuit components. Wafers may alsoinclude semiconductor wafers, silicon-containing wafers, patterned orunpatterned wafers, glass plates, masks, and the like. A pass-through110 may be located between the polishing section 102 and the cleaningand drying section 104. The pass-through 110 may be an opening betweenthe polishing section 102 and the cleaning and drying section 104 thataccommodates the transfer of wafers 108.

The polishing section 102 may include one or more polishing stations114. In the embodiment illustrated in FIG. 1 , the polishing section 102includes four polishing stations 114, referred to individually aspolishing stations 114A-114D. The polishing section 102 may includefewer than or more than four polishing stations 114. Each of thepolishing stations 114 may include a polishing pad. The polishing padsare referred to individually as polishing pads 116A-116D. The polishingpads 116A-116D may rotate against surfaces of the wafers 108 to performvarious polishing processes. One or more slurries (not shown) may beapplied between a substrate and a polishing pad to process thesubstrate. For example, a slurry may remove a specific thickness orlayer of a substrate. In some embodiments, the slurries may includecorrosion inhibitors and other chemicals that may process the wafers108.

The polishing section 102 may include a plurality of heads that maintainthe wafers 108 against the polishing pads 116A-116D during polishing.For example, each of the polishing stations 114 may include a head. Inthe embodiment of FIG. 1 , the polishing stations 114 include fourheads, referred to individually as heads 120A-120D, wherein each of theindividual polishing stations 114 may include or be associated with asingle head.

The heads 120A-120D may secure the wafers 108 therein as the heads120A-120D are transported to and from the polishing stations 114. Forexample, the heads 120A-120D may secure the wafers 108 therein as theheads are transported between load cups 124 and the polishing stations114. The polishing section 102 depicted in FIG. 1 includes two load cups124, referred to individually as a first load cup 124A and a second loadcup 124B. The load cups 124 may transport wafers 108 between the heads120A-120D and wafer exchangers 130. In some embodiments, the polishingsection 102 may include a single load cup or more than two load cups.

The CMP system 100 illustrated in FIG. 1 includes two wafer exchangers130, referred to individually as a first wafer exchanger 130A and asecond wafer exchanger 130B. In some embodiments, the CMP system 100 mayinclude one or more than two wafer exchangers 130. The first waferexchanger 130A may rotate in a first direction 132A and the second waferexchanger 130B may rotate in a second direction 132B, which may beopposite the first direction 132A. In some embodiments, the first waferexchanger 130A and the second wafer exchanger 130B may rotate in thesame direction.

The cleaning and drying section 104 may include a robot 136, such as awet robot, that may transfer wafers 108 through the pass-through 110.For example, the robot 136 may load and remove wafers 108 from the firstwafer exchanger 130A and/or the second wafer exchanger 130B at a firstrobot access location 172A and a second robot access location 172B. Therobot 136 may also transfer wafers 108 between various stations (notshown) in the cleaning and drying section 104 and the wafer exchangers130. The robot 136 may access the wafers 108 from the wafer exchangers130 at other robot access locations.

Reference is now made to FIG. 2 , which illustrates an enlarged, top,plan view of the first wafer exchanger 130A. The first wafer exchanger130A may be substantially similar or identical to the second waferexchanger 130B. The first wafer exchanger 130A may include a pluralityof blades 234. For example, the first wafer exchanger 130A may includethree or more blades 234. Fewer blades, such as two or more blades, mayalso be employed. In the embodiment of FIGS. 1 and 2 , the first waferexchanger 130A includes three blades 234, which are referred toindividually, as a first blade 234A, a second blade 234B, and a thirdblade 234C. In the view of FIG. 2 , the third blade 234C is partiallyobscured by a wafer 208 received thereon. The blades 234 may be orientedto provide even spacing between the blades 234. For example, the threeblades 234 of FIG. 2 may be oriented 120° apart relative to a rotationpoint 236. The first wafer exchanger 130A may rotate about an axis(e.g., a vertically-extending axis) centered at the rotation point 236.Other embodiments of the first wafer exchanger 130A may includedifferent numbers of blades 234 that may be spaced at different angles.

The blades 234 may be coupled to a support member 238 that may includethe rotation point 236. The blades 234 may be, but need not be,substantially similar or identical to each other. The followingdescription references the first blade 234A, which may be representativeof all the blades 234 in the wafer exchangers 130 (FIG. 1 ). The firstblade 234A may include an arm 240 that may be attached to the supportmember 238. As described in greater detail below, the arm 240 may besized to be received in a portion (e.g., a notch 352A—FIG. 3 ) of thefirst load cup 124A. The arm 240 may be connected to a first framemember 242A and a second frame member 242B, which both may be connectedto a third frame member 242C. In some embodiments, the frame members242A-242C and the arm 240 may be integrally formed. The frame members242A-242C may define boundaries of an opening 244 in the first blade234A. As described in greater detail below, the opening 244 may be sizedand/or configured to enable spray emitted from a nebulizer (e.g.,nebulizer 356—FIG. 3 ) to pass through the opening 244. The blades 234may have other configurations.

The blades 234 may include supports 246 (a few labelled) that supportsubstrates located on the blades 234. Reference is made to the thirdblade 234C where the wafer 208 is illustrated supported by the supports246. The supports 246 may prevent the surface of the wafer 208 fromcontacting the frame members 242A-242C of the third blade 234C, whichmay cause damage to the wafer 208.

Reference is now made to FIG. 3 , which illustrates a top, plan, view ofthe first load cup 124A and the third blade 234C located therein. Thefirst load cup 124A may be, but need not be, substantially similar oridentical to the second load cup 124B (FIG. 1 ). The first load cup 124Amay include a wafer station 350 that has an annular shape. In someembodiments, the wafer station 350 may have other shapes. The waferstation 350 may move vertically to place wafers onto the third blade234C and to remove wafers from the third blade 234C. For example, thethird blade 234C may remain fixed in the vertical direction as the waferstation 350 moves vertically relative to the third blade 234C.

The wafer station 350 may include a notch 352A, wherein the arm 240 ofthe third blade 234C is received in the notch 352A as the wafer station350 moves in the vertical direction. The wafer station 350 may alsoinclude a notch 352B and a notch 352C that may receive the third framemember 242C of the third blade 234C as the wafer station 350 moves inthe vertical direction. A wafer may rest on raised features on the waferstation. As the wafer station 350 moves in an upward direction andremoves a wafer from the third blade 234C, the wafer is positionedwithin a plurality of pins 354 (e.g., which may create a pocket tocenter the wafer).

The first load cup 124A may also include a nebulizer 356, wherein thenebulizer 356 may spray fluids (e.g., deionized water) onto the thirdblade 234C, a substrate (not shown in FIG. 3A) located on the thirdblade 234C, and/or a head located above the first load cup 124A. Thenebulizer 356 may include first nozzles 358A (noted by horizontal lines)that may rinse a wafer received on the third blade 234C. The nebulizer356 may include between ten and eighteen first nozzles 358A. In someembodiments, the nebulizer 356 may include between thirteen and fifteenfirst nozzles 358A that may provide between 1.5 liters per minute (lpm)and 2.1 lpm of a rinse solution. In some embodiments, the nebulizer 356may include second nozzles 358B (noted by vertical lines) that may rinsea membrane. The nebulizer 356 may include between five and nine secondnozzles 358B that may provide between 4.0 lpm and 6.0 lpm of a rinsesolution. The nebulizer 356 may include third nozzles 358C (noted bydiagonal lines) that may rinse portions of a head, such as a gap betweenthe head (e.g., head 120D—FIG. 4A) and a wafer (e.g., wafer 208—FIG.4A). The nebulizer may include between two and four third nozzles 358Cthat may provide about between 2.0 lpm and 4.0 lpm of rinse solution. Insome embodiments, the nebulizer 356 may include fourth nozzles 358D(noted by crossed lines) that may rinse a retaining ring (not shown) ina head. The nebulizer may include between two and four fourth nozzles358D that provide between 1.0 lpm and 4.0 lpm of rinse solution. Thenebulizer 356 may include other numbers and configurations of nozzlesand/or other flow rates of rinse solution.

The nozzles 358A-358D may be independently controlled. For example, thefirst nozzles 358A may be controlled independent of the second nozzles358B. As shown in FIG. 3 , the configuration of the third blade 234C andthe configuration of the nozzles 358A-358D is such that the third blade234C does not block any of the nozzles 358A-358D. For example, theconfiguration of the frame members 242A-242C and the opening 244 doesnot block any of the nozzles 358A-358D. This configuration of the framemembers 242A-242C and the nozzles 358A-358C may enable one or more ofthe heads 120A-120D (FIG. 1 ) to be rinsed without obstruction by ablade (e.g., the third blade 234C). In some embodiments, the nebulizer356 remains stationary within the first load cup 124A. Therefore, thenebulizer 356 may be coupled to supplies of rinse solution (not shown)by way of fixed pipes rather than flexible tubing. The fixed pipes mayhave reduced maintenance compared to flexible tubing.

The wafer station 350 may include other features that accommodate thefirst blade 234A and/or the nebulizer 356. For example, the nebulizer356 may have tabs that support the fourth nozzles 358D. The waferstation 350 may have corresponding notches 359A-359C that accommodatethe tabs. Thus, the wafer station 350 may move relative to the nebulizer356 without being impeded by the tabs.

Reference is now made to FIG. 4A, which illustrates an example of thehead 120D located proximate the first load cup 124A. The first load cup124A may include or be attached to a support plate 460. The first waferexchanger 130A may be coupled to the support plate 460 by way of a shaft462. A motor 464, such as a servo motor, may rotate the shaft 462 in thefirst direction 132A (FIG. 1 ) or the second direction 132B (FIG. 1 ).Rotation of the shaft 462 rotates the first wafer exchanger 130A aboutan axis extending through the shaft 462 and/or the rotation point 236.

The nebulizer 356 may be coupled to the support plate 460 by way of oneor more support members 466. In some embodiments, the support member 466may maintain the nebulizer 356 in a fixed position relative to thesupport plate 460. Fluid lines (not shown) may be coupled to thenebulizer 356. For example, four fluid lines, one for each of thedifferent types of nozzles 358A-358D, may be coupled to the nebulizer356.

The wafer station 350 may be moveable in a vertical direction relativeto the support plate 460. For example, the wafer station 350 may bemoveable in a downward or Z− direction and upward in a Z+ directionrelative to the support plate 460. The wafer station 350 may be in afirst location when it is spaced from a wafer 208 supported on the thirdblade 234C. The wafer station 350 may be in a second location when it islocated proximate a head 120D. A support member 468 may couple the waferstation 350 to an actuator 470 that provides vertical movement of thewafer station 350 relative to the support plate 460.

The first load cup 124A of FIG. 4A is shown in a retracted positionwhere the wafer station 350 is moved in the Z− direction so that thethird blade 234C of the first wafer exchanger 130A may move into and outof the first load cup 124A unimpeded. For example, the wafer 208 issupported on the supports 246 of the third blade 234C and the waferstation 350 is located below and spaced from the third blade 234C.

Reference is now made to FIG. 4B, which illustrates the first load cup124A in an extended position. For example, the wafer support 350 hasmoved upward in the Z+ direction to the second location, so as to removethe wafer 208 from the third blade 234C or to move the wafer 208proximate the head 120D. In the position of the wafer station 350illustrated in FIG. 4B, the wafer 208 rests on raised features of thewafer station 350. Other actions may take place to transfer the wafer208 to the head 120D.

In use, the actuator 470 may lower the wafer station 350 by moving thewafer station 350 in the Z− direction to the first location where ablade may enter the first load cup 124A unimpeded. The motor 464 maythen rotate the shaft 462, which rotates the first wafer exchanger 130A.Rotation of the first wafer exchanger 130A may stop when a blade, suchas the third blade 234C, with the wafer 208 located thereon is receivedin the first load cup 124A. The head 120D may move to a location abovethe first load cup 124A. The actuator 470 may then move the waferstation 350 upward in the Z+ direction to the second location where thewafer 208 is proximate the head 120D. The head 120D may grasp the wafer208 and move the wafer 208 to one or more of the polishing stations 114(FIG. 1 ) where a polishing process may be applied to the wafer 208.

When the wafer processing is complete, the head 120D may return with thewafer 208 to a location above the first load cup 124A. The actuator 470may move the wafer station 350 in the Z+ direction to the first locationwhere the wafer station 350 may receive the wafer 208 onto raisedfeatures of the wafer station 350. The actuator 470 may then lower thewafer station 350 in the Z− direction to where the wafer 208 istransferred to the supports 246 of the third blade 234C. The actuator470 may continue to lower the wafer station 350 in the Z− direction to alocation where the third blade 234C may move from the first load cup124A unimpeded.

In some embodiments, sensors (not shown) may be located in the firstload cup 124A and may sense the presence of the wafer 208. Sensors mayalso detect the presence of the wafer 208 in the head 120D. Duringloading of the wafer 208 into the head 124D, sensors may determine thatno wafer is located on the wafer station 350. The wafer station 350 maythen rise in the Z+ direction toward the wafer 208. When the wafer 208transfers to the wafer station 350, sensors may detect the presence ofthe wafer 208 on the wafer station 350. The wafer station 350 may thencontinue rising in the Z+ direction to the head 120D where sensors inthe head 120D detect the presence of the wafer 208. The wafer 208 maythen be loaded into the head 120D. During unload from the head 120D, thesensors may detect that the wafer 208 has been unloaded from the head120D and is present on the wafer station 350. The sensors on the waferstation 350 may also detect the absence of the wafer 208 as the wafer208 transfers to the third blade 234C. The chemical mechanical polishingCMP system 100 may include other sensors.

During the above-described processes, the nebulizer 356 may rinseportions of the first blade 234A, the head 120D, the wafer station 350and/or, the wafer 208. For example, the first nozzles 358A may rinse thewafer 208 after the wafer 208 has been polished. In some embodiments,the wafer 208 may be rinsed while the wafer 208 is in the head 120D andbefore the wafer 208 is transferred to the wafer station 350. In someembodiments, the wafer 208 may be rinsed when the wafer 208 is locatedin the first load cup 124A. In some embodiments, the first waferexchanger 130A may rotate an empty blade into the first load cup 124A.The lack of a substrate in the first load cup 124A may enable thenebulizer 356 to rinse various portions of the head.

Reference is now made to FIGS. 5A-5D where the operation of the firstwafer exchanger 130A and the second wafer exchanger 130B in conjunctionwith other components of the CMP system 100 are described. Wafers withcross-hatching have been polished or processed by the polishing stations114 or other components and are to be transported to the robot 136.Wafers with diagonal hatching have been received from the robot 136 andare to be transported to the polishing stations 114. Empty circlesrepresent blades in the first wafer exchanger 130A and the second waferexchanger 130B that do not have wafers located thereon.

The processing illustrated in FIGS. 5A-5D commences at FIG. 5A wherefirst blades (indicated by the reference numeral 1) are empty. Secondblades (indicated by the reference numeral 2) contain substrates thathave been processed by the individual polishing stations 114 and arereturned to the first load cup 124A and the second load cup 124B. Thirdblades (indicated by the reference numeral 3) contain substrates thathave been received from the robot 136. During the stage depicted in FIG.5A, heads (not shown in FIG. 5A) unload substrates into the first loadcup 124A and the second load cup 124B and onto the second blades. Inaddition, new wafers are loaded from the robot 136 onto the thirdblades.

The first wafer exchanger 130A may rotate in the first direction 132Aand the second wafer exchanger 130B may rotate in the second direction132B to reach the configuration illustrated in FIG. 5B. The firstblades, which may be empty, may be received in the first load cup 124Aand the second load cup 124B. The nebulizer 356 (FIG. 3 ) may rinse theheads located above the first load cup 124A and the second load cup 124Bwithout being impeded by a wafer located between the heads and thenebulizers. The empty blades may also be rinsed. In the configurationillustrated in FIG. 5B, the robot 136 may unload the processed wafersfrom the second blades.

The first wafer exchanger 130A may rotate in the first direction 132Aand the second wafer exchanger 130B may rotate in the second direction132B to reach the configuration illustrated in FIG. 5C. The robot 136may load wafers onto the first blades. In addition, the wafer exchangers130 may unload wafers from the third blades to the heads and the headsmay transport the wafers to the polishing stations 114. FIG. 5Dillustrates the return of the wafers from the polishing stations 114 tothe load cups 124. The first wafer exchanger 130A may rotate in thefirst direction 132A and the second wafer exchanger 130B may rotate inthe second direction 132B to reach the configuration illustrated in FIG.5A where the processes are repeated.

The process illustrated in FIGS. 5A-5D enables faster processing timerelative to traditional CMP systems and methods. For example, the waferexchangers 130 move wafers and blades to robot access locations (e.g.,robot access locations 172A and 172B—FIG. 1 ) for the robot 136, so therobot 136 may have more time for unloading and loading wafers 108. Thewafer exchangers 130 allow for faster cycle time by enabling parallelprocessing of wafers 108. For example, wafers 108 that have completedpolishing may be unloaded and, in parallel, new wafers 108 may be loadedinto the wafer exchangers 130. Therefore, the process relieves the robot136 from being the bottleneck for wafer movements.

The movement of the wafer station 350 (FIG. 3 ) enables the waferexchangers 130 to move solely on a single horizontal plane. Therefore,vertical movement, which may be time consuming, of the wafer exchangers130 is not performed. As shown in FIGS. 5A-5D, the wafer exchangers 130may operate with an empty blade, which enables the heads to be rinsed bythe nebulizer 356 when the empty blades are located in the load cups124. The blades of the wafer exchangers 130 may be rinsed at the sametime. In the embodiment depicted in FIGS. 5A-5D, every third blade thatenters the load cups 124 is empty, which enables rinsing of the headafter two wafers have been processed.

Referring to FIG. 6 , which illustrates a top plan view of anotherembodiment of the CMP system, some embodiments of the CMP system 100 mayinclude one or more rinse stations that are accessible by the waferexchangers 130. The embodiment of the CMP system 100 of FIG. 6 includesa first rinse station 670A that is accessible by the first waferexchanger 130A and a second rinse station 670B that is accessible by thesecond wafer exchanger 130B. In the embodiment of FIG. 6 , the wafers108 located on the wafer exchangers 130 may be in locations includingthe rinse stations 670A or 670B and the load cups 124. In the embodimentof FIG. 6 , the rinse stations 670A, 670B may be in the same locationsas the robot access locations 172A, 172B where the wafers 108 areaccessible to the robot 136.

Reference is now made to FIG. 7 , which illustrates a top plan view ofthe first rinse station 670A, which may be identical or substantiallysimilar to the second rinse station 670B (although they need not be).The first rinse station 670A may include a basin 772 that may collectcleaning fluids that would otherwise overspray into the polishingsection 102 (FIG. 1 ). The first rinse station 670A may include anebulizer 774 located within the basin 772. The nebulizer 774 may besimilar to the nebulizer 356 (FIG. 3 ), but may only include nozzles 776that are configured to rinse a substrate (not shown in FIG. 7 ) locatedat the first rinse station 670A. The nozzles 776 may be configured so asnot to be impeded by a blade of the first wafer exchanger 130A locatedat the first rinse station 670A. In some embodiments, the layout and/orconfiguration of the nozzles 776 may be identical or substantiallysimilar to the layout and/or configuration of the first nozzles 358A(FIG. 3 ) of the nebulizer 356. For example, the nebulizer 774 mayinclude between ten and eighteen nozzles 776 that provide between 1.0lpm and 4.0 lpm of rinse fluid. Referring to FIG. 6 , the wafers 108 maybe rinsed by the first rinse station 670A and the second rinse station670B. The first rinse station 670A and the second rinse station 670B mayinclude other features (not shown) that clean the wafers. The firstrinse station 670A and the second rinse station 670B may serve to keepthe wafers wet, especially after polishing.

In some embodiments, wafers 108 may rest on and/or between supports 246such that wafers 108 may be moved without being gripped. In someembodiments, different spray patterns may be emitted by nozzles 358A,358B, 358C and/or 358D. In some embodiments, one or more hard stops (notshown) may be used to limit vertical motion of the wafer station 350(e.g., to limit how low or high the wafer station 350 may travel duringwafer exchange operations). Any suitable mechanism may be used to moveheads 120A-120D between polishing stations 114 and load cups 124.

The foregoing description discloses only example embodiments.Modifications of the above-disclosed apparatus and methods which fallwithin the scope of this disclosure will be readily apparent to those ofordinary skill in the art.

What is claimed is:
 1. A load cup comprising: a wafer station configuredto receive a wafer, the wafer station moveable in a vertical directionbetween a first location where the wafer station is spaced from a waferand a second location where a wafer is received by the wafer station;and a notch in the wafer station, the notch sized to receive a portionof a blade configured to support a wafer as the wafer station movesbetween the first location and the second location.
 2. The load cup ofclaim 1, further comprising a nebulizer, wherein the nebulizer includesone or more upward-oriented nozzles.
 3. The load cup of claim 2, whereinthe nebulizer includes two or more sets of nozzles, wherein each set ofnozzles is coupled to a different fluid source.
 4. The load cup of claim2, wherein the nebulizer is in a fixed location within the load cup. 5.The load cup of claim 2, wherein the nebulizer remains in a fixedlocation within the load cup during movement of the wafer station. 6.The load cup of claim 1, wherein the wafer station comprises an annularbody.
 7. The load cup of claim 6, comprising a plurality of pins thatproject from a top of the annular body to center the wafer as the waferstation is raised to the second position.
 8. The load cup of claim 6,wherein the annular body of the wafer station surrounds and isvertically movable relative to a nebulizer that includes a nebulizerbody that supports a plurality of upward-oriented nozzles.
 9. The loadcup of claim 8, wherein nebulizer body has an outwardly-extending tabthat fits into a corresponding notch in an inner surface of the annularbody of the wafer station.
 10. The load cup of claim 8, wherein thenebulizer is in a fixed location within the load cup.
 11. The load cupof claim 6, wherein the notch comprises a channel extending from aninner surface to an outer surface of the annular body.
 12. The load cupof claim 11, further comprising at least one second notch, each secondnotch comprising a recess extending inwardly from the inner surface ofthe annular body and partially but entirely through the annular body.13. The load cup of claim 12, further comprising a plurality of secondnotches.
 14. The load cup of claim 6, wherein the notch comprises arecess extending inwardly from the inner surface of the annular body andpartially but entirely through the annular body.
 15. A method of movingsubstrates, comprising: providing a wafer exchanger including two ormore blades, each of the two or more blades configured to receive awafer, the two or more blades rotatable about an axis on a singlehorizontal plane, and the two or more blades movable between at least aload cup and a robot access location; placing a first wafer onto a bladeof the wafer exchanger located at the robot access location; placing asecond wafer from a head onto a blade of the wafer exchanger located atthe load cup; rotating the wafer exchanger to a position where thesecond wafer is located at the robot access location; removing thesecond wafer from the wafer exchanger; rotating the wafer exchanger to aposition where the first wafer is located in the load cup; placing thefirst wafer into the head; and placing a third wafer from the robotaccess location onto a blade of the wafer exchanger.
 16. The method ofclaim 15, further comprising: rotating an empty blade into the load cup;positioning a head above the load cup; and rinsing at least one of theempty blade and the head.
 17. The method of claim 16, wherein rinsing atleast one of the empty blade and the head includes spraying at least oneof the empty blade and the head with a liquid provided from a nebulizerlocated at a fixed position in the load cup.
 18. The method of claim 15,further comprising: providing a rinse station; rotating the waferexchanger to a position where a wafer is located in the rinse station;and rinsing the wafer located in the rinse station.